Whoah! I just checked out your thread on your 3D model Chevysrule and it's looking great so far!
In regards to your question- You're not missing anything as far as depth goes, orthographic projections can be limited in such regards, especially so when it's something as detailed as the MA37. One way around it is to use "hidden lines" which are a series of dashes to show areas that are blocked by other faces but on the MA37 it would have been more of a mess than a help as there's so many recessed areas.
As a way to help with this I've started including links to all my reference pictures that I use to help show recessed/hidden areas and how different parts relate to each other. Hope that helps.
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